微生物缓解镉对水稻的毒害研究进展  

Advances in microbial mitigation of cadmium toxicity in rice

作　　者：卓晨 陈琪 苏增强 黎华寿 陈桂葵 贺鸿志 ZHUO Chen;CHEN Qi;SU Zengqiang;LI Huashou;CHEN Guikui;HE Hongzhi(Key Laboratory of Agro-Environment in the Tropics of Ministry of Agriculture,College of Natural Resources and Environment of South China Agricultural University,Guangzhou 510642,China)

机构地区：[1]华南农业大学资源环境学院,农业部华南热带农业环境重点实验室,广州510642

出　　处：《应用与环境生物学报》2020年第5期1154-1160,共7页Chinese Journal of Applied and Environmental Biology

基　　金：国家重点研发计划项目(2017YFD0800903);广东大学生科技创新培育专项资金项目(pdjh2019b0086);华南农业大学大学生创新创业训练计划项目(201810564001);清远市科技计划项目(2019DZX005);中山市社会公益科技研究项目(2019B2004)资助。

摘　　要：当前水稻是重金属超标最为严重的粮食作物,安全耕种是镉(Cd)中轻度污染区域农田利用的优先解决方案,对水稻可以通过降低Cd在土壤中的生物有效性和阻止其经由水稻根系吸收及向稻米的转运实现安全生产.近年来国内外研究表明利用微生物菌剂可以缓解Cd对水稻的毒害作用并降低籽粒Cd含量.本文主要就近年来国内外关于微生物缓解Cd对水稻的胁迫效果及其机理的最新研究进展进行综述.能缓解Cd对水稻毒害的微生物包括细菌、真菌和绿藻等,其中以细菌居多,同时,不同微生物耐Cd能力差异巨大.接种微生物可使水稻籽粒Cd含量降低20%-74.2%,但仅有部分能降低到可供食用的水平.微生物缓解Cd对水稻毒害作用主要机理包括:降低土壤中Cd的生物可利用度(微生物细胞直接固定或产生胞外分泌物固定Cd)、调控水稻对Cd的吸收转运(促进根系铁膜形成、改变转运蛋白基因的表达、改变Cd在水稻中的分布和化学形态)、提高水稻抗氧化能力(提高抗氧化酶活性和抗氧化物质含量)、分泌促生长物质(植物激素等)、改变土壤理化性质和微生物群落组成等.这些研究表明微生物在提高水稻Cd抗性和降低水稻籽粒Cd含量方面具有不错的应用潜力,但当前相关研究依然存在微生物筛选原则不合理、菌株筛查范围有限、研究多限于实验室水培或盆栽实验、籽粒Cd降幅有限等问题;此外,微生物调控水稻对Cd的吸收转运等的机制尚不清楚;今后应针对性地加强微生物缓解Cd对水稻毒害的机理研究和大田应用评估工作,以期早日实现这一环境友好技术的推广应用.(图1表2参60)At present, rice(Oryza sativa L.) is the food crop with the most excessive heavy metal content. A solution for safe cultivation is a priority for farmland that is located in moderately and lightly cadmium(Cd)-polluted areas. Safe production of rice can be realized by reducing the bioavailability of Cd in soil and preventing its uptake by rice roots and translocation to grains. In recent years, many studies have shown that through the use of microbial agents, the toxic effect of Cd on rice can be alleviated, and the content of Cd in grains can be reduced. This paper reviewed the recent advances in microbial mitigation of Cd stress on rice and its mechanisms over the past five years. The latest research results show that microorganisms that can alleviate the toxicity of Cd to rice include bacteria, fungi, and green algae, among which bacteria are the majority. At the same time, the resistance of different microorganisms to Cd varies greatly. Microbial inoculation reduced Cd content in rice grains by 20%-74.2%, but only some of the microorganisms could reduce the Cd content to the recommended edible level. The main mechanisms of microbial mitigation of the toxic effects of Cd on rice include:(1) Reducing the biological availability of Cd in soil through fixing by microbial cells directly or by extracellular secretion produced by microbial cells.(2) Regulating the absorption and transportation of Cd by rice by promoting root iron membrane formation, by changing transport protein gene expression, altering distribution, and chemical forms of Cd in rice.(3) Enhancing the antioxidant capacity of rice, i.e., the activity of antioxidant enzymes and antioxidant content in plants.(4) Promoting the secretion of growth-promoting substances, such as plant hormones.(5) Altering soil physical and chemical properties, as well as the soil microbial community composition. These studies indicate that the application potential of microorganisms in promoting Cd resistance in rice and reducing Cd content in grains is tremendous, but the

关 键 词：水稻 微生物 镉 重金属胁迫 

分 类 号：X172[环境科学与工程—环境科学]